Answer
$\sqrt {\frac{61}{14}}$
Work Step by Step
Distance formula is given as:
$d=\frac{|a \times b|}{|a|}$
Cross product: $a \times b=\lt 6,-3,4\gt$
$|a \times b|=\sqrt {6^2+(-3)^2+4^2}=\sqrt {61}$
$d=\frac{\sqrt {61}}{\sqrt {14}}$
or, $d=\sqrt {\frac{61}{14}}$